This invention relates to pressurized, aerosol formulations of fixative for hair finishing known as hair-holding sprays or simply hair sprays. Although hair sprays such as plunger sprays and rubber-bulb aerosol sprays are known for use by the individual, and compressed-air sprays are known for use at the professional beauty salon, the overwhelming proportion of commercially distributed hair sprays are sold as pressurized cans with finger-controlled valves built to deliver bursts of aerosols containing a hair fixative. The hair fixative composition normally contains a film-forming polymer, a plasticizer, a solvent, a perfume oil, one or more functional additives, and a propellant. The resin, the plasticizer, and the propellant are often comprised of mixtures.
The ideal hair spray composition is difficult to create because it should satisfy at least four sets of criteria. An environmentally sound hair spray composition would not contain a halocarbon propellant which is said to contribute to destruction of the earth's ozone layer. It would not contain a hydrocarbon propellant which would be flammable. It would not contain methylene chloride in the propellant because that compound may be carcinogenic, irritates the eye and skin, attacks the seal of the metal can, attacks the gaskets in the valve mechanism of the aerosol can, and may be a narcotic.
Although almost all commercial hair spray compositions contain ethanol as a solvent for the film-forming resin and plasticizers, that alcohol is disfavored because it can give beauticians, who are continuously exposed to it, upper respiratory infections, and irritations of the nose and skin. Alcoholic formulations are also dangerous because they are flammable.
The user wants a hair spray composition which gives good fixative properties, is easily washed out, is not tacky or gummy, has no irritating fumes, generates no static, functions well at high humidity, and is not expensive.
From the functional point of view on the hair, the spray composition should provide high curl retention, good combability, no flaking, good sheen and luster, no static charge, no heaviness or other resistance to combing, and no hair breakage or "split ends".
With the compositions hitherto known these sets of criteria are difficult to meet.